Benquo

Their conclusion?

Oxidative stress drives the need for sleep, and sleep is when the body does its oxidative cleanup.

The body's main intracellular antioxidant is glutathione, a small molecule made from three amino acids, glutamate, cysteine, and glycine.

In many contexts, glycine is the bottleneck for glutathione production.

You have plenty of the other two ingredients, but not enough glycine to keep up.

If you are glycine deficient, you cannot make enough glutathione, you clear ROS more slowly during sleep, and you need more sleep to achieve the same degree of clearance.

That is a complete mechanistic chain from glycine deficiency to increased sleep need, and it is entirely independent of the NMDA temperature pathway.

Most people could use more glycine.

Glycine is classified as a non-essential amino acid because the body can make it primarily from another amino acid called serine.

But the body only produces about 3 grams per day.

Estimated total requirements range from 10 to 60 grams per day depending on health status because glycine is consumed in enormous quantities by the production of glutathione, creatine, heme, purines, bile salts, and collagen.

In the ancestral environment this was not a problem.

Traditional diets included collagen-rich connective tissue such as skin, tendons, cartilage, and bone broth, which is about 33% glycine.

Modern diets built around muscle meat and discarding connective tissue cut glycine intake dramatically.

One group of researchers estimated that most people adapt to this deficit by reducing collagen turnover, letting damaged collagen accumulate with age, and that this may contribute to arthritis, poor skin quality, and other consequences of aging.

Others have noted that markers of glycine deficiency appear in the urine of vegetarians, people on low-protein diets, children recovering from malnourishment, and pregnant women.

Heading.

Fever is plan B for fighting infection.

Glycine supports plan A. Fever slows pathogen replication, makes immune cells move faster and multiply more, helps them engulf pathogens more effectively, triggers the production of protective stress response proteins, and speeds antibody production.

But it is metabolically expensive, roughly 10-13% increase in metabolic rate per degree Celsius, and causes significant collateral discomfort and tissue stress.